Calypso Deimos Leda Phobos
V2 Missile Sputnik 1 WAC Corporal Explorer 1
Biplanetary systems Binary planets Twin systems Double planets
Mars Europa Titan Io
5 7 9 3
The Drake Equation The Sagan Equation The Hoyle Equation The Hawking Equation
Ganymede Callisto Titan Io
Discovery Atlantis Enterprise Columbia
93 million km/second 186 million km/second 149 million km/second 299 million km/second
Kuiper Belt Jupiter Ring System Orbiting Neptune Asteroid Belt